comparison common.cpp @ 392:78fed0d4c108 api-inversion

Include some necessary information in struct adb.

Now the struct adb contains a database fd, the flags used to open that
fd (so that we can later tell if it was for write or not) and a database
header pointer.

audiodb_open() is now responsible for filling in all of that
information.  To do that, it needs to take an open(2) flag; that's good,
because it means that the call to open(2) is no longer invoking
undefined behaviour.  (Also, the previous version of audiodb_open()
leaked an fd).  Unfortunately, that means we have broken ABI and API
compatibility.  (Fortunately, we have fewer than 12 users).

Use audiodb_open() in audioDB::initDBHeader().

We've temporarily(?) put acquire_lock(int, bool) in the API header; that
means we need to include <stdbool.h> and compile C files with -std=c99.
Do so.

Make audiodb_close() free resources allocated by audiodb_open().

Include a struct adb * field in the audioDB C++ object...
... which lets us actually implement memory-correctness, by
audiodb_close()ing the database in audioDB::cleanup().

[ The lock is, I think, correctly disposed of; man fcntl(2) on Linux
  says that the locks are released once any file descriptor relating to
  the file is closed, and we close the fd in audiodb_close(). ]

 #include "audioDB.h"
+extern "C" {
+#include "audioDB_API.h"
+}
 
 #if defined(O2_DEBUG)
 void sigterm_action(int signal, siginfo_t *info, void *context) {
   exit(128+signal);
 }

   /* FIXME: maybe we should use a real source of entropy? */
   gsl_rng_set(rng, time(NULL));
 }
 
 void audioDB::initDBHeader(const char* dbName) {
-  if ((dbfid = open(dbName, forWrite ? O_RDWR : O_RDONLY)) < 0) {
-    error("Can't open database file", dbName, "open");
-  }
-
-  get_lock(dbfid, forWrite);
-  // Get the database header info
-  dbH = new dbTableHeaderT();
-  assert(dbH);
-  
-  if(read(dbfid, (char *) dbH, O2_HEADERSIZE) != O2_HEADERSIZE) {
-    error("error reading db header", dbName, "read");
-  }
-
-  if(dbH->magic == O2_OLD_MAGIC) {
-    // FIXME: if anyone ever complains, write the program to convert
-    // from the old audioDB format to the new...
-    error("database file has old O2 header", dbName);
-  }
-
-  if(dbH->magic != O2_MAGIC) {
-    std::cerr << "expected: " << O2_MAGIC << ", got: " << dbH->magic << std::endl;
-    error("database file has incorrect header", dbName);
-  }
-
-  if(dbH->version != O2_FORMAT_VERSION) {
-    error("database file has incorrect version", dbName);
-  }
-
-  if(dbH->headerSize != O2_HEADERSIZE) {
-    error("sizeof(dbTableHeader) unexpected: platform ABI mismatch?", dbName);
-  }
+  adb = audiodb_open(dbName, forWrite ? O_RDWR : O_RDONLY);
+  if(!adb) {
+    error("Failed to open database", dbName);
+  }
+  dbfid = adb->fd;
+  dbH = adb->header;
 
   CHECKED_MMAP(char *, db, 0, getpagesize());
 
   // Make some handy tables with correct types
   if(forWrite || (dbH->length > 0)) {